<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    .container {
      width: 1000px;
      margin: 0 auto;
      font-size: 0;
      /* border: 1px solid #000; */
    }

    /* 左浮动 */
    .left-float {
      float: left;
    }

    /* 清除浮动 */
    .claer-float {
      content: "";
      display: block;
      clear: both;
    }

    .header {
      width: 100%;
      height: 60px;
    }

    .header-left,
    .header-center,
    .header-right {
      background-color: #5cadff;
    }

    .header>.header-left {
      width: 20%;
      height: 100%;
    }

    .header>.header-center {
      width: 50%;
      height: 100%;
      margin: 0 10px;
    }

    .header>.header-right {
      width: 28%;
      height: 100%;
    }

    .content {
      width: 100%;
      height: 400px;
      margin-top: 10px;
      font-size: 0;
    }

    .content>.content-left {
      width: 50%;
      height: 100%;
      background-color: #5cadff;
      margin-right: 10px;
    }

    .content>.content-right {
      width: 49%;
      height: 100%;
      /* background-color: #5cadff; */
    }

    .content>.content-right>.content-right-top {
      width: 100%;
      height: 50%;
      /* background-color: #5cadff; */
      margin-bottom: 10px;
      /* font-size: 0; */
    }

    .content>.content-right>.content-right-bottom {
      width: 100%;
      height: 47.5%;
      background-color: #5cadff;
    }

    .content-right-top>.item1 {
      width: 31%;
      height: 100%;
      background-color: #5cadff;
    }

    .content-right-top>.item2 {
      width: 31%;
      height: 100%;
      background-color: #5cadff;
      margin: 0 17px;
    }

    .content-right-top>.item3 {
      width: 31%;
      height: 100%;
      background-color: #5cadff;
    }

    .footer {
      width: 100%;
      height: 60px;
      background-color: #5cadff;
      margin-top: 10px;
    }
  </style>
</head>

<body>
  <div class="container">

    <!-- 头部 -->
    <div class="header">
      <div class="header-left left-float"></div>
      <div class="header-center left-float"></div>
      <div class="header-right left-float"></div>
    </div>

    <!-- 内容区域 -->
    <div class="content">
      <div class="content-left left-float"></div>
      <div class="content-right left-float">
        <div class="content-right-top">
          <div class="item1 left-float"></div>
          <div class="item2 left-float"></div>
          <div class="item3 left-float"></div>
        </div>
        <div class="content-right-bottom"></div>
      </div>
    </div>

    <!-- 底部 -->
    <div class="footer"></div>
  </div>
</body>

</html>